Complex electronic and/or data processing subassemblies, having a multi-processor and multi-bus structure, and evolving, under difficult environmental conditions must fulfill a number of requirements; high temperature stability, good mechanical behaviour, and also high stability to electromagnetic disturbing fields.
Furthermore, for 16 or 32-bits multi-bus technology data sytems it is necessary to provide a sufficient number of connector pins or points on each card; approximately 400 connector pins is about the number required for these types of technologies.
Similarly, in order to minimize the number of cards, it is worthwhile to produce high-density integration cards. This is also necessary to provide as means for the exchange of heat and for the dissipation of this heat which is generated in the components.
There currently exist standards for the format or size of electronic cards. This standarization allows easy integration and maintenance, harmonizing of the requirements for the installation of the subassemblies, modularity ensuring interchangeability between the various subassemblies, and guarantees satisfactory climatic behaviour, both mechanical and electrical. By way of example, the SEC size or format (standardized electronic cards) is presently in use in certain military devices. This standard defines cards sizes of 123 mm.times.170 mm. This size is sufficiently small for bearing the mechanical stresses, such as vibrations, shaking and shocks. But in the conventional structure this type of card only comprises a connector plug of 96 pins, possibly extensible to 144 or 200 pins which is insufficient to meet the requirements of a 16 or 32 bit multi-bus structure.
Another format or size utilized for civil applications, for a 32 bit DLX calculator, for example, is the format known as "double Europe" in which the dimensions of the cards are 320 mm.times.320 mm. These cards comprise each four connectors of 96 pins, two on each of two parallel ridges. Cards having this format do not satisfy the requirements that exist in difficult environmental conditions, for example, those imposed by military systems.
Conventionally, the connector plugs of CEN (Cartes electroniques Normalisees) format electronic cards are connected through the intermediary of a connector called "socket or female connector", placed on a bracket, the cards sliding into slide-bars orthogonal at the bottom of the receptacle. Thus, the pins and the contacts are opposite one another once the card is positioned in the basket. Furthermore, the connector pins disposed on the opposite edge of the card, for double Europe format cards, are connected by the front face, the interconnecting with the outside environment being thereby achieved through the front face. The spacing of the connector pins in these 96 pin connectors is 2.54 mm, the standardized spacing of the cards in the basket being either 12.7 mm, or 7.62 mm. The heat dissipation is generally provided in the frame forming the mechanical skeleton of the card, the form of which is adapted to the power to be dissipated.
The known structures do not allow to overcome the problems indicated herein-above. In particular, they cannot be utilized on 32 bits technology with the number of connector pins approaching or exceeding 400, taking into account the severe environmental requirements and offering a high-density integration.